Measurement Techniques for Atmospheric Trace Gas Concentrations and Other Parameters

2008 ◽  
pp. 113-134 ◽  
Author(s):  
Ulrich Platt ◽  
Jochen Stutz
Keyword(s):  
Measurement Techniques ◽  
Trace Gas ◽  
Atmospheric Trace Gas

scholarly journals Long open-path measurements of greenhouse gases in air using near-infrared Fourier transform spectroscopy

2018 ◽  
Vol 11 (3) ◽  
pp. 1549-1563 ◽  
Author(s):  
David W. T. Griffith ◽  
Denis Pöhler ◽  
Stefan Schmitt ◽  
Samuel Hammer ◽  
Sanam N. Vardag ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Near Infrared ◽  
Measurement Techniques ◽  
Trace Gas ◽  
Gas Composition ◽  
Spatial Averaging ◽  
Mid Infrared ◽  
Open Path ◽  
Atmospheric Trace Gas

Abstract. In complex and urban environments, atmospheric trace gas composition is highly variable in time and space. Point measurement techniques for trace gases with in situ instruments are well established and accurate, but do not provide spatial averaging to compare against developing high-resolution atmospheric models of composition and meteorology with resolutions of the order of a kilometre. Open-path measurement techniques provide path average concentrations and spatial averaging which, if sufficiently accurate, may be better suited to assessment and interpretation with such models. Open-path Fourier transform spectroscopy (FTS) in the mid-infrared region, and differential optical absorption spectroscopy (DOAS) in the UV and visible, have been used for many years for open-path spectroscopic measurements of selected species in both clean air and in polluted environments. Near infrared instrumentation allows measurements over longer paths than mid-infrared FTS for species such as greenhouse gases which are not easily accessible to DOAS.In this pilot study we present the first open-path near-infrared (4000–10 000 cm−1, 1.0–2.5 µm) FTS measurements of CO2, CH4, O2, H2O and HDO over a 1.5 km path in urban Heidelberg, Germany. We describe the construction of the open-path FTS system, the analysis of the collected spectra, several measures of precision and accuracy of the measurements, and the results a four-month trial measurement period in July–November 2014. The open-path measurements are compared to calibrated in situ measurements made at one end of the open path. We observe significant differences of the order of a few ppm for CO2 and a few tens of ppb for CH4 between the open-path and point measurements which are 2 to 4 times the measurement repeatability, but we cannot unequivocally assign the differences to specific local sources or sinks. We conclude that open-path FTS may provide a valuable new tool for investigations of atmospheric trace gas composition in complex, small-scale environments such as cities.

scholarly journals Long open path measurements of greenhouse gases in air using near infrared Fourier transform spectroscopy

2017 ◽  
Author(s):  
David W. T. Griffith ◽  
Denis Pöhler ◽  
Stefan Schmitt ◽  
Samuel Hammer ◽  
Sanam N. Vardag ◽  
...  
Keyword(s):  
Near Infrared ◽  
Measurement Techniques ◽  
Trace Gas ◽  
Small Scale ◽  
Gas Composition ◽  
Spatial Averaging ◽  
Mid Infrared ◽  
Open Path ◽  
Atmospheric Trace Gas

Abstract. In complex and urban environments, atmospheric trace gas composition is highly variable in time and space. Point measurement techniques for trace gases with in situ instruments are well established and accurate, but do not provide spatial averaging to compare against developing high resolution atmospheric models of composition and small scale meteorology with resolutions of the order of a kilometre. Open path measurement techniques provide path average concentrations and spatial averaging which, if sufficiently accurate, may be better suited to assessment and interpretation with such models. Open path Fourier Transform Spectroscopy (FTS) in the mid infrared region, and Differential Optical Absorption Spectroscopy (DOAS) in the UV and visible, have been used for many years for open path spectroscopic measurements of selected species in both clean air and in polluted environments. Compared to the mid infrared, near infrared instrumentation allows measurements over longer paths than mid IR FTS, for species such as greenhouse gases which are not easily accessible to DOAS. In this pilot study we present the first open path near infrared (4000–10 000 cm−1, 1.0–2.5 μm) FTS measurements of CO2, CH4, O2, H2O and HDO over a 1.5 km path in urban Heidelberg, Germany. We describe the construction of the open path FTS system, the analysis of the collected spectra, precision and accuracy of the measurements, and the results from a four-month trial measurement period in July–November 2014. The open path measurements are compared to calibrated in situ measurements made at one end of the open path. There are small but significant differences between in situ and open path measurements coincident in time which reflect local sources and sinks and the way in which they are sampled by the point and path-averaged measurements. Open path FTS may provide a valuable new tool for investigations of atmospheric trace gas composition in complex, small scale environments such as cities.

scholarly journals Estimation of trace gas fluxes with objectively determined basis functions using reversible-jump Markov chain Monte Carlo

2016 ◽  
Vol 9 (9) ◽  
pp. 3213-3229 ◽  
Author(s):  
Mark F. Lunt ◽  
Matt Rigby ◽  
Anita L. Ganesan ◽  
Alistair J. Manning
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Parameter Space ◽  
Spatial Domain ◽  
Monte Carlo Algorithm ◽  
Trace Gas ◽  
Reversible Jump ◽  
Pseudo Data ◽  
Atmospheric Trace Gas

Abstract. Atmospheric trace gas inversions often attempt to attribute fluxes to a high-dimensional grid using observations. To make this problem computationally feasible, and to reduce the degree of under-determination, some form of dimension reduction is usually performed. Here, we present an objective method for reducing the spatial dimension of the parameter space in atmospheric trace gas inversions. In addition to solving for a set of unknowns that govern emissions of a trace gas, we set out a framework that considers the number of unknowns to itself be an unknown. We rely on the well-established reversible-jump Markov chain Monte Carlo algorithm to use the data to determine the dimension of the parameter space. This framework provides a single-step process that solves for both the resolution of the inversion grid, as well as the magnitude of fluxes from this grid. Therefore, the uncertainty that surrounds the choice of aggregation is accounted for in the posterior parameter distribution. The posterior distribution of this transdimensional Markov chain provides a naturally smoothed solution, formed from an ensemble of coarser partitions of the spatial domain. We describe the form of the reversible-jump algorithm and how it may be applied to trace gas inversions. We build the system into a hierarchical Bayesian framework in which other unknown factors, such as the magnitude of the model uncertainty, can also be explored. A pseudo-data example is used to show the usefulness of this approach when compared to a subjectively chosen partitioning of a spatial domain. An inversion using real data is also shown to illustrate the scales at which the data allow for methane emissions over north-west Europe to be resolved.

Atmospheric trace gas measurements at Palmer Station, Antarctica: 1982?83

1984 ◽  
Vol 2 (1) ◽  
pp. 65-81 ◽  
Author(s):  
E. Robinson ◽  
W. L. Bamesberger ◽  
F. A. Menzia ◽  
A. S. Waylett ◽  
S. F. Waylett
Keyword(s):  
Trace Gas ◽  
Palmer Station ◽  
Gas Measurements ◽  
Atmospheric Trace Gas

The sap flow-based assessment of atmospheric trace gas uptake by three forest types in subtropical China on different timescales

2018 ◽  
Vol 25 (28) ◽  
pp. 28431-28444 ◽  
Author(s):  
Xia Chen ◽  
Ping Zhao ◽  
Yanting Hu ◽  
Xiuhua Zhao ◽  
Lei Ouyang ◽  
...  
Keyword(s):  
Sap Flow ◽  
Trace Gas ◽  
Forest Types ◽  
Subtropical China ◽  
Gas Uptake ◽  
Atmospheric Trace Gas

Research on Open-Path Detection for Atmospheric Trace Gas CO Based on TDLAS

2015 ◽  
Vol 42 (2) ◽  
pp. 0215003 ◽  
Author(s):  
姚路 Yao Lu ◽  
刘文清 Liu Wenqing ◽  
刘建国 Liu Jianguo ◽  
阚瑞峰 Kan Ruifeng ◽  
许振宇 Xu Zhenyu ◽  
...  
Keyword(s):  
Trace Gas ◽  
Open Path ◽  
Atmospheric Trace Gas ◽  
Path Detection

scholarly journals Design and application of a mobile ground-based observatory for continuous measurements of atmospheric trace gas and criteria pollutant species

2015 ◽  
Vol 8 (8) ◽  
pp. 3481-3492 ◽  
Author(s):  
S. E. Bush ◽  
F. M. Hopkins ◽  
J. T. Randerson ◽  
C.-T. Lai ◽  
J. R. Ehleringer
Keyword(s):  
Spatial Scales ◽  
Point Sources ◽  
Trace Gas ◽  
Mobile Laboratory ◽  
Gas Emissions ◽  
Trace Gas Emissions ◽  
Criteria Pollutants ◽  
Position Data ◽  
Health Related ◽  
Atmospheric Trace Gas

Abstract. Ground-based measurements of atmospheric trace gas species and criteria pollutants are essential for understanding emissions dynamics across space and time. Gas composition in the lower 50 m of the atmosphere has the greatest direct impacts on human health as well as ecosystem processes; hence data at this level are necessary for addressing carbon-cycle- and public-health-related questions. However, such surface data are generally associated with stationary measurement towers, where spatial representation is limited due to the high cost of establishing and maintaining an extensive network of measurement stations. We describe here a compact mobile laboratory equipped to provide high-precision, high-frequency, continuous, on-road synchronous measurements of CO2, CO, CH4, H2O, NOx, O3, aerosol, meteorological, and geospatial position data. The mobile laboratory has been deployed across the western USA. In addition to describing the vehicle and its capacity, we present data that illustrate the use of the laboratory as a powerful tool for investigating the spatial structure of urban trace gas emissions and criteria pollutants at spatial scales ranging from single streets to whole ecosystem and regional scales. We assess the magnitude of known point sources of CH4 and also identify fugitive urban CH4 emissions. We illustrate how such a mobile laboratory can be used to better understand emissions dynamics and quantify emissions ratios associated with trace gas emissions from wildfire incidents. Lastly, we discuss additional mobile laboratory applications in health and urban metabolism.

Sign in / Sign up

Export Citation Format

Share Document